Oh, I'd suggest be specific with any questions...
Why?
1) It's too easy to assume all the differences are down to Linux being better developed & therefore 'more functional' than the likes of AOS4 - true, but not the point & does not explain the whole story.
Consider QNX which has had 20 years of continuous professional development & will match Linux feature-for-feature while booting even faster than OS4!
2) Your Linux_guru may not be aware that these Os's go about providing their functions in fundamentally different ways... This may lead to an explanation based on incorrect assumptions. Get then to stick to what they know ( Linux ) possibly followed by questions like: 'If it did it so-and-so wouldn't that be more efficient so cutting boot times..?'

A good Amiga example of these differences is the TCP stack. AFAIA all AOS TCP stacks are based on a 'monolithic' model rather than 'interrupt-driven' as is the OS itself.
The OS starts quickly & responds quickly to 'events' but starting the TCP stack is anything but... This is not as one would expect a result of time taken to do the connection housekeeping but simply because these stacks are based off models more akin to Linux/Windows...